1. Hello ANTLR: ANother Tool for Language Recognition 2. Where we can use ANTLR? 3. Why just not use regular expression language? 4. Tools under ANTLR umbrella 5. ANTLR basic syntax 6. ANTLR on real example

1. Using ANTLR on real
example
convert “string combined” queries into
parameterized queries

2. Simon Wiki says:

ANTLR (pronounced Antler), or ANother Tool for Language
Recognition, is a parser generator that uses LL(*) parsing.

ANTLR takes as input a grammar that specifies a language and
generates as output source code for a recognizer for that
language. A language is specified using a context-free grammar
which is expressed using Extended Backus–Naur Form (EBNF).

ANTLR allows generating lexers, parsers, tree parsers, and
combined lexer-parsers. Parsers can automatically generate
abstract syntax trees which can be further processed with tree
parsers. ANTLR provides a single consistent notation for specifying
lexers, parsers, and tree parsers. This is in contrast with other
parser/lexer generators and adds greatly to the tool's ease of use.

3. Used at least in following products:

Drools, JBoss rule engine (DRL DSL)

Hibernate, Java ORM (HQL DSL)

NHibernate, .NET ORM (HQL DSL)

Groovy, language for JVM

Jython, language for JVM

4. Where we need ANTLR?

Parsing a text stream of formal data

Parsing a text stream of incomplete formal data

Complex parsing

Parsing with good error handling

Writing Domain-Specific Language

You have enough time and some data to parse...

5. Why just not use regular
expression language?

In most cases you should go with RegEx

SO: “RegEx is a text search tool. If all you need to do is pull
strings out of strings then it's often the hammer of choice.”

SO: “ANTLR is a parser generator. If you need error messages
and parse actions or any of the complicated things that
come with a interpreter/compiler then it's a good option.”

SO: “ANTLR has perfect support for "error-messages": they
show line/column numbers and what was wrong. RegEx
doesn't have this support.”

ANTLR is a something (a-lot-of-things) on top of regular
expression language.

6. ANTLR parsing workflow

7. Tools under ANTLR umbrella
ANTLR3 Code Generation Targets:
•
Java, JavaScript (in sync with development)
•
C, C++, C#, Objective C, Ruby (almost in sync)
•
Python, ActionScript (current with 3.1 instead of
3.4)

8. Tools under ANTLR umbrella
ANTLR Grammars:
Java, C, C++, ECMAScript, ANTLR, C#,
PHP, Verilog, x86 Assembler, ISO SQL
2003, PL/SQL, Clojure, XPath, Pascal,
GraphViz Dot, Fortran, Python, CSS,
Objective C, Lua, Ruby, Eiffel, ECMA
CIL (.NET), Classic ASP, CORBA IDL

9. Tools under ANTLR umbrella
Editors, IDEs, etc:
•
ANTLRWorks, GUI IDE. http://antlr.org/works/
•
Eclipse, NetBeans, JetBrains IDEA, Visual Studio
integration.
•
VIM syntax highlighter. https://github.com/rollxx/vim-
antlr
•
ANTLR-Mode for Emacs. http://antlr-
mode.sourceforge.net/

10. ANTLRWorks. Editor window

11. ANTLRWorks. Interpreter window

12. Ambigious path visualization

13. ANTLRWorks. Interactive
debugger

14. Eclipse. ANTLR integration

15. JetBrains IDEA. ANTRL integration

16. Sample syntax. CSV grammar

17. Real example. Test cases
• Query without any parameters
• Query with concat and variable
• Query with dotted and escaped table names and single quote in sql
• Query with function call and func args concat
• Query with function call with several func args
• Query with nested function call with several func args
• Query with concat and two variables
• Insert query with four params
• Query with dotted param and function name and funciton arg
• Endline symbol will be dropped from query
• Single line comment will be dropped from query
• Strip single quote only if it next to parameter
• Query with like keyword (FAILED)
• Refactor multiline query (FAILED)

18. Real example. Syntax tree
strsql = "SELECT * FROM TABLE_NAME WHERE
FIRST_FIELD = " & DOTTED.PARAM_VAR & "
AND SECOND_FIELD = " &
DOTTED.FUNC_CALL(DOTTED.FUNC_ARG)

19. Grammar:1. Options, tokens

20. Grammar:2. Lexer/parser members

21. Grammar:3. Top-level elements

22. Grammar:4. End

23. Questions are Welcome!
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